"By 1975, Iannis Xenakis had created four Polytopes: in Montreal (1967), Persepolis (1971), and two at the Cluny abbey in Paris (1972-1973). In this book, the author presents some working documents on these Polytopes. A Polytope is a multimedia performance with sounds (electroacoustic music for Cluny, four recorded orchestras for Montreal, natural sounds for Persepolis) and visual effects (lights for Montreal, lights and lasers for Cluny, the illumination of fire in the night for Persepolis). The author also presents some documents on the Philips Pavilion at the 1958 Brussels World Fair."